High temporal resolution ECG-gated scintigraphic angiocardiography (radionuclide cineangiography) is a computer-based, radiotracer imaging procedure that allows non-invasive visualization of the chambers of the working heart at rest, during bicycle exercise, during therapeutic intervention, etc. The procedure yields quantitative measures of left ventricular function such as ejection fraction, peak ejection rate, etc. Work is continuing to assess the accuracy of these data in humans and to establish findings for the method in selected disease categories. Variations of this technique are being explored.